1. Field of the Invention
The present invention relates to a folding baby carriage and more particularly, to a folding baby carriage folded so that four wheels may approach each other back and forth and from side to side and more particularly, to a folding baby carriage in which its rigidity is enhanced.
2. Description of the Background Art
FIGS. 1 and 2 show a baby carriage disclosed in Japanese Unexamined Patent Publication No. 8-58599. FIG. 1 shows an opened state of the baby carriage and FIG. 2 shows a folded state of the baby carriage. As can be clear when FIG. 1 is compared with FIG. 2, when the baby carriage 1 is folded, four wheels 4 and 6 approach each other back and forth and from side to side.
The illustrated baby carriage 1 comprises a body 2 mainly constituted by bar-shaped members, and a seat hammock 3 mounted on the body 2 to form a seat. The baby carriage body 2 comprises a pair of front legs 5 having the front wheels 4, a pair of rear legs 7 having the rear wheels 6, a pair of handrail members 8 positioned above both sides of the seating surface, a pair of inverting members 9 turnably mounted on rear legs 7, and a push bar 10 having an inverted U-shaped configuration, connected to rear end portions of the pair of handrail members 8 and extending upward.
The push bar 10 has a pair of side vertical bars 11 linearly extending in the vertical direction so as to be parallel to each other, and an upper portion connecting member 12 connecting upper ends of the pair of side vertical bars 11. The upper portion connecting member 12 has a pair of rotating members 12a provided so as to receive the side vertical bars 11 and rotate around the side vertical bars 11, and a center member 12b connecting the pair of rotating members 12a. The rotating member 12a and the center member 12b are connected so as to be allowed to be bent as shown in FIG. 2.
A lower frame structure positioned above the four wheels 4 and 6 and forming a seating surface portion of a seat is folded so that the four wheels 4 and 6 may approach each other back and forth and from side to side. The inverted U-shaped push bar 10 extending to rise upward from both sides of the seating surface portion is bent forward by protruding the center member 12b forward to reduce the dimension in the width direction, in the folded state shown in FIG. 2.
According to the baby carriage disclosed in Japanese Unexamined Patent Publication No. 8-58599, since it is folded while a dimension in the width direction is reduced, the push bar 10 is constituted so as to be allowed to be bent forward. More specifically, each rotating member 12a of the upper portion connecting member 12 is allowed to be rotated around each side vertical bar 11, and the edge of each rotating member 12a is connected to the center member 12b so as to be allowed to be bent.
As described above, when the push bar 10 is constituted by the plural members and those members are connected at joint portions so as to be allowed to be bent, the baby carriage can be folded while its dimension in the width direction is reduced. However, because of the joint portion connecting the adjacent members so as to be allowed to be bent, even in the opened state of the baby carriage, the joint portion of the inverted U-shaped push bar 10 becomes wiggly or flexible. Because the joint portion becomes wiggly or flexible, the push bar 10 is easily twisted or distorted. Since the twist or distortion beginning at the push bar 10 is transmitted to the lower frame structure, the rigidity of the whole baby carriage in the opened state is lowered.